Stent grafts are often positioned in the descending aorta, for example for treating aneurysms. However, sometimes it is necessary to implant a stent graft in the ascending aorta that is in close proximity to the aortic valve. Positioning a stent graft in the ascending aorta requires maneuvering around the aortic arch and into the ascending aorta. Passing of the deployment device over the aortic arch can cause loss of the control over the deployment device because of the significant curvature of the aortic arch. Furthermore, as the ascending aorta is in close proximity to the aortic valve, it is important when positioning stent grafts in the ascending aorta that they are placed accurately without gaps between the aorta and the graft.